Recent years have been witness to a wide array of technological advancements that have purveyed many aspects of modern life. New types of communication systems, for instance, have been developed and deployed that provide for the effectuation of many different types of communication services. Ready access to communication systems are required by many through which to effectuate communication services, and many of the communication services have become, or are, practical necessities of modern society.
Technological advancement shall likely continue, and, when such technological advancements are deployed in communication systems, new communication services shall likely become available. Generally, when deployed, technological advancements permit communication services to be effectuated more efficiently at increased data communication rates, or in manners to provide better for successful recovery of the informational content of the data that is communicated even when the data is communicated in adverse communication conditions.
Digital communication techniques are amongst the technological advancements that have been implemented in communication systems. The use of digital communication techniques provides various communication advantages. For instance, through the use of digital communication techniques, data redundancies can be removed prior to the communication of the data. And, as a result, the improved communication efficiencies permit data throughput rates, i.e., the rates at which the data can be communicated, to be increased relative to a corresponding communication system that fails to make use of digital communication techniques.
A radio communication system is a communication system that utilizes radio channels by which to communicate the data between communication stations that are parties to a communication session by which a communication service is effectuated. The radio channels are defined upon a portion of the electromagnetic spectrum, and the radio channels are defined, at least in part, by the frequencies upon which the data is communicated. The communication stations that are operable pursuant to a communication session to communicate data therebetween operate variously to convert data that is to be communicated into a form capable of communication on the communication channel and to detect the data communicated thereon. Once detected, the informational content of the data is recovered.
Use of radio communication systems is sometimes preferred over use of wireline communication systems due to various advantages inherent to, or permitted by, communication of data by way of radio channels. Because a wireline connection is not required to interconnect the communication stations between which data is communicated in a radio communication system, use of a radio communication system permits communications to be effectuated even when wireline connections cannot easily be formed. Additionally, as the need for a wireline connection between the communication stations is obviated, a radio communication system is amenable for implementation as a mobile communication system in which one or more communication stations that are parties to a communication session are provided communication mobility.
A cellular communication system is a type of radio communication system. A cellular communication system is typically implemented as a two-way communication system that provides for full duplex communications. The networks of cellular communication systems have been deployed over significant portions of the populated areas of the world. And, usage levels of cellular communication systems are large and growing, sometimes approaching the levels of the levels of usage of conventional telephonic systems. And, while cellular communication systems were first used, and continue to be used to effectuate voice communication services, the new generations of cellular communication systems increasingly provide for the effectuation of high speed data services. Additionally, data messaging services are amongst the communication services that increasingly are effectuated by way of a cellular communication system.
Data messages are communicated, for instance, between the network part of the communication system and a mobile node positioned within an area encompassed by the communication system. Data messages that are to be terminated at the mobile node are sent by the network part of the communication system by way of down-link, or forward-link, channel to the mobile node. And, data messages originated at the mobile node are sent upon up-link, or reverse-link, channels to the network part.
Data messages are, in digital cellular communication systems, typically formatted into data packets. The data message is communicated by sending one or more data packets that contain the informational content of the data message by way of an appropriate channel formed between the mobile node and the network part. A data packet is typically formatted to include a header part and a payload part. The payload part includes the informational content of the message, and the header part includes, amongst other things, routing information. The routing information is used to route the data packet to its intended destination.
The routing information needed by which to route the data packet to its intended destination is dependent upon the location of the mobile node when the data packet is sent therefrom. And, because the mobile node is inherently mobile, the routing information required to route the data packets to its intended destination might differ at different times, depending upon the location of the mobile node and through which portions of the network part that the data packet shall be routed to be delivered to its intended destination.
The mobile node is associated with a home network. When the mobile node is positioned in an area encompassed by its home network, the data packet is communicated, by way of a radio channel, to the home network of the mobile node and then routed through the network for delivery to its destination. However, when the mobile node roams beyond its home network, i.e., the mobile node roams into an area encompassed by another network and not the home network, different routing information is required to route the data packet to its intended destination. The routing of the data packet sometimes utilizes tunneling in which a so-called tunnel is formed by way of which the data packet is routed to its intended destination. Otherwise, the data packet is delivered to its destination without tunneling.
In order for the mobile node to be permitted to communicate by way of a non-home network, arrangements must be made by the operators, i.e., the carriers, of the respective networks to permit the mobile node access to the non-home network to communicate the data packet therethrough. And, if an area is encompassed by more than one cellular communication system, an arrangement is sometimes made with one, and not another, of the operators of the respective non-home networks. When a data message formed of the one or more data packets is to be communicated when the mobile node is positioned in such area, the message is communicated by way of the non-home network whose operator maintains the roaming agreement, or other affiliation, with the operator of the home network of the mobile node.
Some conventional mobile nodes include a host-routing table at which the routing information needed to populate the header portion of the data packet formed at the mobile node is stored. In a conventional mobile node, the host routing table is sometimes only a single entry. That is to say, the host routing table contains host routing information that permits routing of the data packet when the mobile node is positioned in a single area. When the mobile node moves, subsequently to be positioned in another area, new routing information must be obtained and downloaded to the mobile node. The additional information is obtained through the generation of a registration request. However, each time in which a registration request is sent by the mobile node, additional radio air resources are used. As the use of the radio air resources to send, and to respond to, the registration request forms overhead signaling, the need conventionally to send the multiple registration requests increases system overhead and reduces the communication capacity of the communication system.
A manner by which to provide the mobile node with routing information that requires lessened amounts of overhead would therefore permit communication capacity of the communication system to be increased.
It is in light of this background information related to communication of data in a packet radio communication system that the significant improvements of the present invention have evolved.